1. Field of the Invention
This invention relates to a sampling device, and more particularly, to a modular sampling device.
2. Related Art
When there is a potential threat of exposure to nuclear, biological or chemical (NBC) materials, precautions are often taken. These precautions can include early detection and warning of the presence of NBC materials. In some cases, it is necessary to take samples in areas where the detection of NBC materials is not routinely done. In these cases, it is necessary to use portable sampling equipment.
In some cases, it is necessary to take two samples, one sample to immediately test for the presence of NBC materials, and a second sample to either archive or subject to a different kind of test. It is also helpful if the sampling media, for example, filters, are easy to install and remove. While various sampling devices have been proposed, the related art fails to teach or disclose such a device.
Boyum et al. (U.S. Pat. No. 5,333,511) discloses a device that draws in air at preset timed intervals through a valve mechanism. The Boyum device does not take two samples in parallel and the sampling media is not easy to install and remove. It also appears to be directed to sampling solely gases, and cannot be used for aerosolizable particulates.
Chinn et al. (U.S. Pat. No. 5,939,647) discloses a surface particle sampling head with a rotating probe. Chinn discloses a device that is set on a surface to create a seal. After the seal is created, air is blown on the surface and particles are funneled to a particle analysis device. The Chinn reference lacks a means for sampling because Chinn performs internal testing with a particle counter. Thus, the Chinn device does not provide a filter, much less dual filters. Chinn also uses compressed gas as an agitator. Chinn also discloses the use of Teflon as one of the main materials. This is disadvantageous, because Teflon tends to hold charge and attract particles, thus preventing effective sampling. The Chinn device does not collect sampling matter onto a filter.
Robinson et al. (U.S. patent application number 2003/00150985) discloses a cassette for use with vortex separation and sampling of particles. Systems that use vertex separation are not adaptable for portable devices because they generally require a vertical orientation to work efficiently. Robinson fails to teach the use of dual filtration.
Lejeune (U.S. patent application number 2004/0043443) teaches two sampling inlets and two filters. However, the Lejeune device does not include a common inlet and is not portable. Because Lejeune draws from two separate inlets, the two filters may not receive the same representative sample. The Lejeune device is also intended to be permanently installed and is not portable.
While the related art generally teaches sampling devices, none of the references teach a portable system capable of taking two similar representative samples where the sampling media is easy to install and remove.